install PyQt5

The following is based on this YouTube video.

$ sudo apt install python3-pyqt5
...
$ python3
>>> import PyQt5
>>>
=======================================================================
$ sudo apt install python3-pyqt5.qtsql
...
$ python3
>>> from PyQt5 import QtSql
>>>
=======================================================================
$ sudo apt install qttools5-dev-tools
...
$ ls -al /usr/lib/x86_64-linux-gnu/qt5/bin/designer
lrwxrwxrwx 1 root root 25 ápr   14 09:38 /usr/lib/x86_64-linux-gnu/qt5/bin/designer -> ../../../qt5/bin/designer

I put a symbolic link on designer to launch it easily.